1. Field of the Invention
This invention relates generally to a method for determining the complexity of illustrations to be displayed and, more particularly, to a method for automatically indexing the complexity of technical illustrations for prospective users by measuring the performance of software which processes the illustrations.
2. Description of the Related Art
In order to effectively operate and maintain any complex equipment system, system personnel must have ready access to usable technical data, in either hard-copy or on-line form, which adequately describes both the operation of the overall system and the operation of the individual pieces of equipment forming the system. The technical data relied on by prospective users, such as system operators and personnel assigned to maintain the system equipment, is normally provided by system designers or authors in the form of one or more technical manuals. It can be appreciated that since in many cases the equipment itself is extremely complex, these manuals must necessarily include both a textual description of the equipment operating and maintenance features, and one or more pictures, drawings or schematics of the equipment which accompany the text. These pictures, drawings or schematics are referred to as "technical illustrations."
Since the technical illustration is, in most cases, critical to an overall understanding of the textual material, and provides essential visual data for training, operation, maintenance or repair of system equipment, the technical illustration must be presented by the author in a format which is both easily understood and readily usable by prospective users.
Recognizing the importance of readily understandable and usable technical illustrations, the author is faced with a choice when preparing the illustration. The author recognizes that the cost of developing readily understandable illustrations is tradable, within limits, against the fact that inexpensive but partially or totally incomprehensible illustrations necessarily result in added costs due to ineffective system operation and unnecessary maintenance costs due to lack of illustration clarity. Thus, the author strives to prepare technical illustrations which, in and of themselves, are readily understandable by the intended user. In addition, the author recognizes that well-designed technical illustrations are also indispensable to the effective use of the textual documents which accompany the illustrations.
Although the need for technical illustrations which may be readily understood is well recognized by the illustration author, it is sometimes difficult for the author to determine a minimum complexity level required of a technical illustration to effectively convey sufficient information to the intended user group. From the viewpoint of the illustration author, the level of illustration complexity is important since complexity affects illustration costs and production time. A corollary of this is that productive utilization of technical illustrations becomes more feasible as the illustrations become optimally informative and the numbers of illustrations required to convey sufficient information are reduced.
From the viewpoint of the illustration user, the complexity of the technical illustration is a function of the inherent complexity of the equipment pictured in the illustration, coupled with the level of detail included. Illustration complexity is significantly influenced by other variables, such as task difficulty, spatial organization of a given set of details, and the level of user sophistication in the task at hand.
For the illustration author, determining the level of prospective user sophistication is critical to a determination of the complexity or amount of detail to be presented in the illustration. On the one hand, novice users benefit from more detail, redundancy and primitive expression than do expert users. Conversely, the performance of an expert may actually be degraded, and a novice may be delayed in becoming an expert, if the only available format for a given set of technical data in illustration form encourages rote imitation without a higher-level understanding of the underlying principles of function or operation of the equipment depicted.
Since system designers or authors frequently do not have the resources or time to create different sets of technical illustrations for different prospective user groups, it can be seen that selecting an optimum technical illustration complexity level for all possible user groups is indeed a difficult task.
Therefore, there is a need for a method for automatically determining and indexing the complexity level of a technical illustration which may be utilized by system authors during preparation and storage of the illustration for future printing. The method should provide an overall index of the complexity of the illustration to permit the author to tailor the illustration to its intended user group. It should be possible to implement the method either during the formation of the technical illustration, or after the illustration has been completed. In addition, it should be possible to implement the method independently of the actual production of the illustration.